INFO: task syz.0.1427:11262 blocked for more than 143 seconds.
      Not tainted 6.17.0-rc1-syzkaller-00022-g07866544e410-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1427      state:D stack:20904 pid:11262 tgid:11261 ppid:10710  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1360
 nfsd_nl_rpc_status_get_dumpit+0xdf/0x1290
 genl_dumpit+0x10b/0x1b0
 netlink_dump+0x6e4/0xe90
 __netlink_dump_start+0x5cb/0x7e0
 genl_family_rcv_msg_dumpit+0x1e7/0x2c0
 genl_rcv_msg+0x5da/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3202f8ebe9
RSP: 002b:00007f3203ede038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f32031b5fa0 RCX: 00007f3202f8ebe9
RDX: 0000000000000000 RSI: 0000200000000180 RDI: 0000000000000008
RBP: 00007f3203011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32031b6038 R14: 00007f32031b5fa0 R15: 00007fff652e7068
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e139ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
3 locks held by kworker/1:2/973:
2 locks held by getty/5675:
 #0: ffff88801fe950a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
2 locks held by sshd/5823:
3 locks held by kworker/u8:5/6870:
 #0: ffff888108aef148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000304fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f537d08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0
2 locks held by syz.7.705/8553:
 #0: ffffffff8f59d330 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e4184c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
3 locks held by syz.0.1427/11262:
 #0: ffffffff8f59d330 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffff88802f3966d0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0
 #2: ffffffff8e4184c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdf/0x1290
2 locks held by syz.4.1733/12441:
 #0: ffffffff8f59d330 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e4184c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x16e/0xb60
3 locks held by syz.1.1791/12638:
 #0: ffffffff8f59d330 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffff8880388726d0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0
 #2: ffffffff8e4184c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdf/0x1290
2 locks held by syz.3.1846/12852:
 #0: ffffffff8f59d330 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e4184c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x16e/0xb60
2 locks held by syz.5.1879/13010:
 #0: ffffffff8f59d330 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e4184c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x16e/0xb60
2 locks held by syz.5.1879/13011:
 #0: ffffffff8f59d330 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e4184c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x16e/0xb60
1 lock held by syz.6.2541/15482:
 #0: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730
1 lock held by syz.0.2542/15486:
2 locks held by syz.2.2543/15495:
 #0: ffffffff8f537d08 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x32a/0x1df0
 #1: ffffffff8e13f978 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted 6.17.0-rc1-syzkaller-00022-g07866544e410-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6870 Comm: kworker/u8:5 Not tainted 6.17.0-rc1-syzkaller-00022-g07866544e410-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:__lock_acquire+0x50c/0xd20
Code: 49 83 c7 28 41 89 c4 48 39 cb 0f 8d d6 00 00 00 48 83 fb 31 0f 83 92 00 00 00 41 8b 07 25 ff 1f 00 00 48 0f a3 05 d4 9f 0a 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 10 03 49 93 eb 40 83 3d 3b 2f
RSP: 0018:ffffc9000304efe8 EFLAGS: 00000007
RAX: 00000000000004f5 RBX: 0000000000000000 RCX: 00000000ffffffff
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88810721d640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8172c195
R10: ffffc9000304f238 R11: ffffffff81ac3890 R12: ffffffffffffff05
R13: 0000000000000001 R14: ffff88810721e1d0 R15: ffff88810721e150
FS:  0000000000000000(0000) GS:ffff8880b861c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056371008b043 CR3: 000000000df36000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000082 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 unwind_next_frame+0xc2/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 dst_cow_metrics_generic+0x56/0x1c0
 icmp6_dst_alloc+0x264/0x420
 ndisc_send_skb+0x41f/0x1440
 addrconf_dad_completed+0x7ae/0xd60
 addrconf_dad_work+0xc36/0x14b0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
